Slide fastener



Dec. 1, 1953 H. HEIMANN ETAL SLIDE FASTENERS 2 Sheets-Sheet 1 Filed March 20, 1951 FIG.

FIGS

FIG. 2

INVENTORS HEINRICH HEIMANN, 8

IRA SHUR Wm fi/ ATTO NEY Dec. 1, 1953 H. HEIMANN ETAL SLIDE FASTENERS 2 Sheets-Sheet 2 Filed March 20, 1951 FEG. 4

INVENTORS Patented Dec. 1,, 1953 UNITED STATS FFECE SLIDE FASTENER Heinrich Heimann, New York, and Ira. Shut,

Floral Park, N. Y., assignors to Waldes Kohinoor, 1110., Long Island City, N. Y., a corporation of New York Application March 20, 1951, Serial No. 216,598

This invention relates to improvements in slide fasteners, and more particularly to an improved construction of a fastener element for use with ed directly on to the tape, a certain number at a time, to form a socalled stringer. It was also known to employ for this purpose two-part molds with the parting line of the mold parts lying in the plane of the tape, and the row of el ment- 'forming cavities in one mold part being the mirror image of the row of cavities in the other mold part.

In practice, such a mold resulted in the formation of symmetrical elements, that is to say, elements which are so constructed as to their locking projections and recesses as to permit the slide fastener to be opened or closed by the slider from either end, and accordingly the two stringers making up the slider can be assembled without regard to the direction in which the coupling projections of the elements point.

Dilficulties arise in forming plastic fastener elements in a two-part mold whose parting line lies in the plane of the stringer tapes as aforesaid. As is generally recognized, the coupling projections and recesses of the elements of one stringer which are to interlock with the corresponding recesses and projections of the elements of the opposite stringer are usually arranged on the side faces of the elements, the projections extending from and the recesses being formed in said side faces. While such does not offer any difiiculty in the formation as by coining of the metal elements of a metal slide fastener, the aforesaid disposition and arrangement of the coupling projections and recesses of the elements of the plastic slide fastener made in a two-part mold requires that they be so shaped as to make possible the separation of the mold parts. It was therefore earlier suggested in the Johnson Patents No. 1,865,393, dated June 28, 1932, and No. 1,891,989, dated December 27, 1932, to extend the recess through the element face (front or rear) angularly adjacent the side face containing the recess, so that the male portion of the one mold part employed to form the recess could be withdrawn therefrom upon completion of the molding operation.

However, the mold of the type disclosed by the ,jection to their use.

3 Claims. (Cl. 24-20513) Johnson patents is not symmetrical as to its two parts and is thus expensive to construct, and

the elements formed by the Johnson mold were found to be lacking in security in the direction normal to the plane of the tapes. These disadvantages were subsequently in part overcome byothers, but the later solutions were themselves not successful because, generally speaking, the plastic elements formed by their pro cedures had the characteristic disadvantage that their coupling projections and recesses engaged each other for half the depth (side face height) only of the elements, thereby lessening the resistance of the fastener to lateral strains exerted thereon in the plane of the tapes. Since plastic slide fasteners are widely used as closures for tight-fitting garments such as girdles, ladies bathing suits and the like, the failure of the prior fastener elements to withstand high lateral ,strains due to their inability to interlock throughout their full depth represents a substantial ob- With-the above in mind, it is a principal object of the present invention to provide an improved plastic fastener element for plastic slide fasteners capable of being molded in a two-part mold characterized by a parting line lying in theplaneof the fastener tapes, whose construction is such that it may and does interlock with an opposite fastener element in a manner providing the greatest possible security against strains acting both in the plane of the tapes and in a direction normal to said plane.

More particularly, the invention aims to provide a plastic fastener element for use in plastic slide fasteners, characterized by coupling means functioning to resist lateral pull imposed thereon by'its tape for the whole depth (side face height) of the element and which is moreover capable of interlocking with an'opposite, eleincnt in such manner that disengagement of the interlocked elements in; direction perpendicularly to the plane-of the tapes is positively precluded; ,Another important object of the invention. is the. provision of 'a plastic fastener element for use in plastic slide fasteners, as characterized in theforegoing, having the additional notable advantage that its upper and lower halves, as defined by the horizontal middle plane of the element corresponding-to the plane of the fastener tape, are identical but reversed with respect to one. another. Thus, the element is identical nal axis, without regard to which of its faces is to provide the front face. Moreover, when assembled with related fastener elements, it is individually reversible with respect to the related fastener elements either of the same row, or of the oppositely disposed elements of the other row with which it is intended to be coupled.

The above and other objects and advantages of a slide fastener according to the invention will appear from the following detailed description thereof, taken with the accompanying drawing, in which Fig. 1 is an enlarged perspective view of improved specially formed plastic fastener ele-: ments of the invention interlocked with a similar but oppositely disposed element;

Fig. 2 is a side elevationlooking into the left side face of the lower fastener element illustrated in Fig. 1;

Fig. 3 is a side elevation looking into the opposite or right side face of the element illustrated in Fig. 2; and

Fig. 4 is a fragmentary View of a plastic slide fastener employing fastener elements according to the invention and illustrating the interlocking engagement of the opposite fastenerelements inplanview. Referring to the drawings, the plastic fastener element illustrated is of'the type adapted to be formed in a'two-part mold whose meeting or parting line lies in the plane of the fastener tapes. tion A, 'which'may be molded directly onto its carrying tape l and'the edge bead ll thereof (FigsJZ- i), or may be initially formed with a tape slot l2 and a cylindrical'opening or bore 13 for the bead; and a'coupling portion B in'which are formed the projections and recesses adapted to provide interlocking engagement with the complemental recesses and projections of two identical adjacent elements of the opposite stringer.

According to the invention, the element is shaped substantially as a rectangular block'having a front or upper face C, a rear or under face D, "a left" side face E, a right side face F, a rear or shank-end face G, and a front-" or coupling end face H, all as viewed in Fig. 1. At this point, it will be observed that terms sucha's front or upper, rear or under side, end, or horizontal and vertical, are used'above or hereinafterto'define the general relationships as" shown in the drawings and are not intended to indicate restriction of the use of the'invention or the'scope'of the appended claims to any particular positionof the element.

According to the invention, the left side face E is formed with avertical through groove or recess Hiwhose ends open through both'the element front 'and rear'ffaces 'C, D, respectively, and which in any horizontal plane has the shape of a widened U. 'said'reee'ss' is widened in its upper half portion by a sub-recess 15 formed as by stepping one side wall [6 of the recess rearwardlyor towards the shank end of theelement, thus to provide a horizontal shelf or shoulder I! which is disposed in the horizontal plane'of the tape IQ and which extends forwardly into the recess. Thus, said one side wall, rather than being continuous, is formed by the lower'wall portion I6, the horizontal shelf [1, and the upperwall portion Hid. 'Said side wall portions I6, 160., together with the other side wall portions l8, lBa (Fig. 2), and thebottom wall l9,are provided with" relief, that is to say;

they are slightly sloped'in opposite direction Such an element comprises ashank poraway from the horizontal middle plane of the element (corresponding to the plane of the tape l0) so as to facilitate separation of the mold parts, and particularly of the male projections thereon which form the recess I4 and its subrecess [5. In Figs. 2 and 3, such sloping has been exaggerated so as to supply shading effects helpful to an understanding of .the element construction.

By reference to Figs. 1 and 4, the depth of the recess I4 is approximately one-third the width dimension of the element, i. e. the distance between the element side faces E and F, and the recess is moreover spaced a substantial distancerearwardly or towards the shank end fromthe coupling end face H. Such results in conjunction -with the companion recess formed in the'other side face of the element, as will be laterdescribed, in the formation of a T-shaped coupling head at the free or coupling end of the fastener element which extends across the full width of the element, but not beyond its side faces E and F, the arms of said coupling head having length and thickness corresponding to the depth and width of a recess 14.

At its coupling end the element is formed with a downwardly opening, half-depth corner recess 22 "defined b'ya top horizontal wall 23 disposed in the plane of the aforesaid shelf I! of the recess 14, a transverse vertical wall 24 normal to the left side face E, and a vertical wall 25 normal to the end face H. Thus, the corner recess 22 opens through the left-side, rear and coupling-end faces of the'element, but is closed on top by its horizontal top wall 23 lying in the plane of the tape II. The side walls 24, 25 of said element are also relieved in manner similar to the relief provided for the side faces of the recess [4, to facilitate withdrawal of the projection of the lower mold part which forms the recess 22.

By reference to Figs. 1 and 3, the right side face F 'of the element maybe said to be an inverted mirror image of the left side face E, being provided with a recess 34 corresponding to the recess l4 and with a sub-recess35 corresponding to the sub-recess l5. However, the right side subrecess 35 opens to the rear or under face D of the element and thus widens the lower half portion of the recess 34 rather than the upper half portion thereof, as in the case of the sub-recess I5; This is achieved by stepping the lower side wall portion 38 of the recess 34 toward the shank-end face G of the element so as to form a shoulder or shelf 31 which, like the shelf If! of therecess l 4, is disposed in the horizontal middle plane of the element, so that the upper wall portion 38a of the recess overhangs the lower sidewall portion38 thereof.

The'right side coupling end of the element is also formed with a half-depth recess 42, but the same is oppositel disposed to the aforesaid corner recessfZZ, that is to say, the recess '42 open through the right side face F, the front face C and the coupling end face H of the ele ment. Said recess is defined. by a bottom horizontal wall' 43 lying in the horizontal middle plane of the element, a vertical transverse wall 44, and a vertical wall 45 disposed normal to the coupling-end face G. It is understood that as with all vertical walls of the element recesses, the recess walls 44, 45 are, relieved to facilitate Withdrawal of the male projection of the mold are cast on their tapes and the opposite stringers assembled as in Fig. 4, the oppositely disposed elements of the stringers interlock as shown in that figure, taken with Fig. 1. According to the interlocking arrangement made possible by the special element construction aforesaid, the coupling heads of any two adjacent elements of the righthand stringer engage for their full depth (side face height) in the through recesses M and 34, respectively, of an intermediate opposite element of the lefthand stringer. Since the opposite elements interlock throughout their .full depth, they provide extremely high security against strains exerted in lateral direction on the fastener. Moreover, due to the oppositely stepped construction of the recess side walls 18, Ito and 38, 38a, taken with the opposite or reverse disposition of the corner recesses 22, 42 of the elements, the oppositely disposed elements also interlock with one another in a direction normal to the plane of the fastener tapes. Thus, as seen in Fig. 4, the left-side corner recess top ,wall 23 and the left-side recess shelf 17 of the upper righthand element abut on the left-side recess shelf I7 and the left-side corner recess top wall 23, respectively, of the upper lefthand element. In similar manner, right-side corner recess bottom wall 43 and right-side recess shelf 3? of the upper righthandelement abut in the right-side recess shelf 3? and the right-side corner recess bottom wall 43, respectively, of the lower lefthand element. Accordingly, relative vertical, 1. e., normal to the planeof the tapes, movement of the oppositely disposed fastener elements is positively precluded. 7 Y 7 I p In addition to the aforesaid advantages, it will be further seen that no special locking projections extending from or corresponding recesses sunk into the element side faces are required to be formed on or in the element by the mold parts, but, instead, the locking projections are contained within the plan contour of the elements themselve and the recesses either extend through or open to one or the other of the upper or under faces of the elements. Stated otherwise, the elements in themselves provide all of the interlocking projections and recesses required to effect secure interlocking of the oppositely disposed elements, both in the plane of the tapes and in a direction normal thereto.

It will also be observed that the upper and lower halves of fastener elements according to the invention, as such halves are defined by the horizontal middle plane thereof, are symmetrical, i. e. identical but reversed. Hence, not only may such fastener elements be readily formed in a two-part mold whose parting line lies in the middle plane of the elements corresponding to the plane of the tapes, but, also, since the elements are identical front and rear, they may be disposed on their tapes without regard to which of their front or rear faces is disposed upwardly, and they are also individually reversible with respect to adjacent or oppositely disposed fastener elements of the fastener.

As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

l. A plastic slide fastener comprising rows of oppositely disposed and individually reversible fastener elements having substantially rectangular block formation and being afilxed at their one ends to their carrying tapes, the other coupling ends of said elements being provided in their opposite side faces with substantially U- shaped recesses extending the full depth thereof and which result in said coupling ends having the form of a T whose cross arms have length and thickness corresponding to the depth and width of said elements, the side face recesses 'of the elements each having a corresponding side wall stepped-to provide a horizontal surface disposed inthe plane of the tapes, the stepping of the side wall of one side-face recess of an element being opposite to that of the side wall of the other side-face recess, whereby one horizontal surface faces towards the front face of the element and the other towards the element rear face, and the coupling ends being each provided in'part by horizontal surfaces disposed inthe plane of the tapes, said corner recesses being oppositely disposed both to one another so that one opens towards the front face and the other towards the rear face of the element, and to the direction in which the-horizontal surface of the side-face recess on the same side of the element faces, the construction and arrangement being such that the coupling ends of theelements of one row thereof having 'interfitting engagement in the side-face recesses of two adjacent elements of the opposite row throughout the depth of said recesses, and the horizontal surfaces of the corner recesses of each coupling end are adapted to abut the oppositely facing horizontal recess surfaces of the two adjacent oppositely disposed elements.

2. A plastic slide fastener comprising rows of oppositely disposed fastener elements having substantially rectangular block formation and being afifixed at their shank ends to their carrying tapes, the coupling ends of said elements being provided in their opposite side faces with substantially U-shaped recesses extending the full depth thereof so as to open through both the front and rear element faces, said recesses being located lengthwise of the elements so as to result in said coupling ends having the form of a T whose cross arms each has length and thickness corresponding substantially to the depth and width of a recess, the side walls of the sideface recesses of each element which are disposed adjacent the shank end thereof being rearwardly and oppositely offset at the element middle plane, said opposite offsetting providing oppositely facing shoulders extending forwardly into said recesses for substantially the full depth thereof, the coupling ends of each element being provided at the corners between the element front-end face and its side faces with shoulder-receiving recesses which extend half the depth of the element and each having a bottom wall which is disposed in the element middle plane, said corner recesses being oppositely disposed with respect to one another whereby one corner recess opens to the front face and the other corner recess opens to the rear face of said element, and each said corner recess being oppositely disposed and substantially complemental to the shoulder of the side-face recess on the same side of the element as said corner recess, the construction and arrangement being such that the upper and lower halves of each element as defined by the middle plane thereof are identical but reversed with I respect to one another, whereby each element is individually reversible with respect to adjacent or oppositeelements of the rows; that the coupling ,end of each element of one row has interfitting engagement in the oppositely facing sideface recesses of the two adjacent oppositely disposed elements of the other row to which said coupling end couples throughout the depth of said recesses, with the shoulders of said oppositely facing side-face recesses being received in thecorner recesses of said coupling end; and

that said coupling end is interlocked with said two oppositely disposed elements in a plane normal to that of the fastener by engagement of the bottom Walls of its said corner recesses with the shouldersof the said oppositely facing side-face recesses.-

3. In a plastic slide fastener, a fastener ele- -mentcomprising a substantially rectangular body molded from plastic material and having a shank portion for attachment to the fastener tape and a coupling portion adapted to be interloclged with two similar but oppositely disposed fastener elements, the element being provided in each of its side faces with a substantially U- dle plane to provide oppositely facing shoulders extending forwardly into said recesses for substantially the full depth of the latter, the coupling end of said element being provided at the corners between the element front-end face and its side faces with recesses for receiving the shoulders of the oppositely facing side-face recesses of said oppositely disposed fastener ele ments and which extend half the depth of said element and each having a bottom wall which is disposed in the element middle plane, said corner recesses being oppositely disposed with respect to one another whereby one corner recess opens to the front face and the other corner recess opens to the rear face of the element, and each said corner recess being oppositely disposed to the shoulder of the side face recess on the same side of the element as said corner recess, the construction and arrangement being such that the upper and lower halves of the element as defined by the middle plane thereof are identical but reversed with respect to one another, whereby said element is turnable about its longitudinal axis without regard to which of its faces is to provide the front face.

HEINRICH HEIMANN. IRA SHUR.

References Cited in the file of this patent UNITED STATES PATENTS Number 

